Question: Simplify the following expression: $z = \dfrac{r - 7}{r + 6} + \dfrac{-3r + 8}{r + 6}$
Answer: Since the expressions have the same denominator we simply combine the numerators: $z = \dfrac{r - 7 - 3r + 8}{r + 6}$ Combine like terms: $z = \dfrac{-2r + 1}{r + 6}$